(DEXTER, Mo.) - A Missouri man has been arrested and charged with "reckless exposure to HIV" after he admitted to having unprotected sex with up to 300 people without disclosing his HIV status, triggering alarm among health officials.

David Lee Mangum, 36, was arrested in Dexter, Mo., on Aug. 27 after his former live-in lover came forward to Dexter police to file a complaint that Mangum had knowingly infected him with HIV. The alleged victim, 28, identified in the complaint as D.B., said that he tested positive for HIV in July of this year, according to a probable cause affidavit filed in Stoddard County court by Det. Cory Mills.

Mangum was arraigned today, but did not enter a plea. A preliminary hearing was set for Sept. 26, a representative for Stoddard County court told ABCNews.com . Bond was set by Judge Stephen Mitchell at $250,000.

Mangum could face a life sentence if convicted. A public defender appointed to Mangum's case did not immediately return calls placed by ABCNews.com.

Stoddard County Prosecuting Attorney Russell Oliver told ABCNews.com that he is urging anyone who engaged in anonymous sex in the area to have an HIV test.

"Essentially our primary focus in this case is to get it onto the public view," Oliver said. "Our concern is for public health. Any individual who may have come into contact with this man, or through Craigslist, if you met a man in Stoddard County and engaged in sex, we'd urge you to get tested and cease all sexual activity. Better safe than sorry."

Mangum and his former boyfriend met via a men-seeking-men ad on Craigslist in October 2012 and engaged in unprotected oral and anal sex, according to the complaint. The two moved in together on Nov. 9, 2012, but the relationship ended in June when D.B. discovered that Mangum had been cheating on him, the complaint states.

The victim also told police that a former female roommate of Mangum had disclosed to her that he had been HIV positive since 2003, and that he has had over 300 sexual partners since he tested positive.

Dexter police were able to interview Mangum on Aug. 26, during which he waived each of his rights and admitted to having unprotected sex with the victim without disclosing his HIV status, and provided authorities with his records from the Stoddard County Health Center, Detective Mills wrote in the probable cause affidavit.

Mangum also admitted to police that he had over 300 sexual partners since testing positive in 2003, and that between 50 and 60 were in Stoddard County, according to the complaint.

When asked why he did not disclose his HIV status to his partners, Mangum said, "fear of rejection."